Introduction

Introduction

Compiled and published by the Bureau of Transportation
Statistics (BTS), U.S. Department of Transportation, National Transportation
Statistics 2002 presents information on the U.S. transportation
system1,
including its physical components, safety record, economic performance,
energy use, and environmental impacts. National Transportation Statistics
2002 is a companion document to the Transportation Statistics Annual
Report, which analyzes the data presented here.

The report has four chapters:

Chapter 1 provides data on the extent, condition, use, and performance
of the physical transportation network.

Chapter 3 focuses on the relationship between transportation and
the economy, presenting data on transportation=s contribution to the
gross domestic product, employment by industry and occupation, and transportation-related
consumer and government expenditures.

In addition, as part of BTS's ongoing effort to identify and assess the extent of data errors, appendix C includes brief discussions of the quality of the data presented in many of the tables. BTS obtained the data in this report from many sources, including federal government agencies, private industry, and associations. Some of the data are based on samples and are subject to sampling variability. Data from all sources may be subject to omissions and errors in reporting, recording, and processing. Documents cited as sources for the tables often provide detailed information about definitions, methodologies, and statistical
reliability.

Generally, data are presented in five-year increments through 1995 and annually thereafter. The web version of the report provides a more comprehensive inventory of the available data than
presented here.

1 The U.S. transportation system comprises six modes: air, highway,
transit, rail, water, and pipelines.